I prefer the s4 because the s5 is glued,
You can easily change yourself parts of the s4 to repair it.
Forget the official documentation !
It is not complicated, it is unclear !
Even if you are a macrosoft windobe user, i advice you to read the first guide i wrote, before following the second one …
/[HOWTO] install /e/ on a Samsung device from a GNU/Linux PC successfully
/[HOWTO] Install /e/ on a Samsung smartphone with Windows easily